Casting machine



Feb. 27, 1951 N. LESTER ET AL 2,543,503

CASTING MACHINE Filed Aug. 6, 1946 3 Sheets-Sheet 1 I ns... 5. h

INVENTORS NATHAN LESTER and THOMAS J. LESTER BY fill/WM ATTORNEYS' 7, 1951 N. LESTER ET AL 2,543,503

CASTING MACHINE Filed Aug. 6, 1946 3 Sheets-Sheet 2 I l7 6 l9 INVENTORSI NATHAN LESTE R and BY THOMASJ.LESTER ATTORNEYS Feb. 27, 1951 N. LESTER ET AL CASTING MACHINE 3 Sheets-$heet 3 Filed Aug. 6, 1946 INVENTORS NATHAN LESTER and THOMAS J. LESTER & Y

S Y E N R O T T A Patented Feb. 27, 1951 CASTING MACHINE Nathan Lester, Shaker Heights, and Thomas J. Lester, University Heights, Ohio, assignors to Lester Engineering Company, Cleveland, Ohio,

a corporation of Ohio Application August 6, 1946, Serial No. 688,612

Claims. 1

The present invention relates generally to improvements in a casting machine for producing, for example, castings from thermoplastic materials and more particularly to improvements in the mechanism and method for actuating the mold cavity forming dies of such machine.

Such casting technique is commonly referred to as injection molding and, as is well known, the high pressures under which plasticized material is forced into a molding cavity defined between separable dies necessitates application of large forces on the dies to retain them in a closed position during casting, and, of course, the machine as a whole must be of strong and rigid construction to safely and effectively withstand such high pressures and large forces. Also, in most casting machines one of the dies is fixed relative to the machine and the other is movable in a hcrizontal direction relative to said fixed die, thus presenting several problems for which solutions have been found but often at excessive cost and extra nuisance and difliculty. Some of the problems concomitant with the use of such machines are the retaining of mold inserts in place during casting, the adaptation of the casting ejecting mechanism to the single movable die and the trimming of the sprue or gate from the casting. As to the retaining of inserts in place, it is evident that special clamping fixtures and adaptors must often be resorted to in order to retain the inserts within the vertically disposed die. As to the ejector mechanism, it can be seen that by making both dies movable, the problem is simplified in that such mechanism can be associated with either die depending on convenience rather than necessity. As to the trimming of the sprue or gate from the casting, it can be seen that if it is in the parting line between the dies and enters the mold cavity from an outer surface thereof, it is a simple matter to trim it off from the outer surface of the casting, as compared with trimming it from some inner surface of the casting, as is generally the case where the sprue or gate is at the center of the dies and the mold cavity is disposed concentrically thereabout. In the latter instance, the sprue or gate could be arranged so that the molding material is injected into the mold cavity from the outer periphery thereof but such off-center arrangement is not feasible primarily because the eccentric leading thus imposed on the dies results in excessive flash on the casting, particularly in the portions thereof farthest away from the sprue. Furthermore, such arrangement is usually not feasible because of the increased vertical ex- 2 tent of the dies and the consequent excess weight thereof.

It is one principal object of this invention to provide in a machine having a horizontally movable platen and a fixed platen, a simple mechanism in which the dies are mounted horizontally, in which both dies are movable, and in which the sprue therefor is in the horizontal parting line between the dies and in communication with the mold cavity at the outer periphery thereof to thus avoid all of the aforesaid typical problems.

It is another object of this invention to provide a mechanism by means of which the horizontally disposed dies can be much more firmly clamped than in the original machine having vertically disposed dies. That is to say that the dies can be clamped together with the same or a greater force than those in the original machine but with much less stress on the toggle linkage associated with the movable platen.

It is another object of this invention to provide a die actuating mechanism in which the dies are positively closed by interengaging wedge surfaces on the platens and on the die carrying members.

It is another object of this invention to provide a die actuatingmechanism which is capable of simultaneously moving the dies in unison away from the injection nozzle of the machine to sever the molding material at a point between the nozzle and the mold cavity and of separating the dies to permit removal of the completed casting.

It is another object of this invention to provide a die actuating mechanism in which the interengaging wedge surfaces of the platens and the dies are disengaged by means of a novel 10st motion connection prior to effecting separation of the dies.

It is another object of this invention to provide novel means for translating relative movement of the platens into relative movement of the dies in a direction transverse to that of said platens.

Additional objects and advantages of the invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawings:

Fig. 1 is a front elevation View, partly in section,

of a portion of a typical machine of which the die actuating mechanism constituting the present invention is a part, such machine being shown with the dies in a closed position;

Fig. 2 is a view similar to Fig. 1 but with the dies in an open position;

Figs. 3, 4 and 5 are detail views of one form of lost motion connection means between the movable platen of the machine and the die carrying members, Fig. 3 being a view of the lefthand end of Fig. 4, and Fig. 5 being a transverse cross section view taken along lin 55 of Fig. 4;

Fig. 6 is a longitudinal center vertical cross section view through the die actuating mechanism showing the dies in a closed position, such view being taken along line 6- 5 of Fig. '7;

Fig. 7 is a transverse vertical cross section view taken along line 7-! of Fig. 6;

Fig. 8 is a central horizontal cross section view taken along line 8--8 of Fig. 6;

Figs. 9, l0, and. 11 are views of a modified form of lost motion connection between the die carrying members and the movable platen of the machine, Figs. 9 and 10 respectively showing the position of such lost motion connection when the dies are in closed and in opened positions, and Fig. 11 showing such lost motion means in perspective; and Figs. 12 and 13 are views corresponding to the upper left hand portion of Fig. 7

but illustrating a modified form of pivotal con- 1 nection between the respective ends of the links and the die carrying members and the lug plates.

Referring now to the drawing, the casting machine as a whole is, except for the features herein embodied, of form substantially identical with that of Lester Patent 2,262,615 issued on Nov. 11, 1941, and such machine, although described herein in relation to the present improvements, is to be regarded as merely typical.

As shown in Figs. 1 and 2, the machine comprises a frame I of generally box type construction, at one end of which an injection cylinder and nozzle assembly 2 is swingably mounted about a vertical axis and at the other end of which is mounted a hydraulic piston and cylinder, not shown, the horizontal rod 3 of which is adapted to reciprocate longitudinally of the base.

The injection cylinder and nozzle assembly 2 generally comprises an injection cylinder 4, a

feed hopper 5 for supplying molding material in granular, chip or finely divided form into the injection cylinder 4, a heated spreader 8 through which the material is forced under pressure by the plunger 1 reciprocable in the injection cylinder 4, and an injection nozzle 8 from which the material in plasticized condition is injected into a mold cavity in communication with the injection nozzle. This assembly is firmly supported vertically with the injection nozzle portion thereof in alignment with the mold cavity sprue opening by means of a suitable adjusting screw 9 threaded into frame 1.

Within frame I and in abutting relation to the end thereof which carries the injection cylinder assembly 2 is a fixed platen I0. Movable horizontally and relative to the fixed platen I0 is a movable platen l l and an auxiliary platen l2, the latter two being adjustable relative to one another by means of a screw it which is rotatable but non-movable longitudinally in one of them and in threaded engagement with the other of them. Any well known means may be employed to eifect rotation of screw 13, as for example by means of a bevel gear and pinion, not shown, in which the pinion is rotated by a crank 4 [4 or the like. The purpose of screw i3, as will become apparent as this description proceeds, is to enable adjustment of platen 12 so that it is spaced a predetermined distance from platen l0 when the toggle linkage, generally indicated at !5, is in die closing position, as shown in Fig. l. The toggle linkage is, of course, merely typical and therefore may be of any desired form, the desired action thereof being to effect rapid low power movement of platen l2 to and from a die closing position and to effect a final high power movement of platen [2 to firmly close the dies. It can be seen from Figs. 1 and 2 that reciprocation of rod 3 in opposite directions will effect,

5 through the linkage i5 which is connected to rod 3, the aforesaid low and high power movements of platen [2. The movements of platens II and [2 are guided in suitable ways l6 fixed to frame I. Platens II and i2 are further guided in their movements by suitable guide rods 5'! disposed on either side of piston rod 3 and secured to platen II and slide-guided in suitable bushings (not shown) in the frame.

Having thus generally described a typical casting machine, reference will now be made to the mechanism for effecting vertical separation of the dies and to the various features incorporated in such mechanism.

Attached to fixed platen ID is an adaptor plate I? having a sprue bushing 18 fitted into a central horizontal opening therein. Secured to the opposite ends of plate 2'! are a pair of lug plates 1 S which are spaced from one another and which project toward platen I2. Plates is are cut away as shown at 28 to provide free access to the die cavities when the dies are in open position as shown in Fig. 2.

Plate I1 is provided with a recess in its face directed toward platen l2 for receiving the ends of a pair of die carrying members 2i and 22, the recess being preferably provided with hardened wedge strips 23 each having a surface slightly inclined from horizontal and engageable with correspondingly inclined surfaces on the die carrying members 2| and 22. While no particular means is illustrated for adjusting the vertical space between the wedge strips 23, it will be apparent to those skilled in the art that any suitable means may be employed, as for example, the wedge strips 23 may be mounted so as to be movable lengthwise along an inclined plane. That is to say that the upper and lower wedge strip sup porting walls of the recess in plate i! may be inclined slightly from horizontals when viewed from the right hand end of Fig. 6. Hardened wedge strips 24 are also preferably fixed in a recess in a plate 25, which plate is secured to the auxiliary platen [2, such strips 24 facing toward the strips 23 and being engageable with the opposite ends of the die carrying members 2| and 22. Strips 24 may also be made adjustable vertically as described above with reference to strips 23.

In the following description and in the claims the die carrying members 2! and 22 are referred to simply as dies, inasmuch as it does not form any part'of this invention to make the actual dies separate of the die carrying members 2! and 22.

Pivotally secured to each plate 19, by means of shoulder screws 26 threaded into each plate [9, are two pairs of links 2'! and 28, all of which are preferably of the same length. The other end of each link 2'! and 28 is pivotally connected to the dies 21 and 22 respectively, as by means of shoulder screws 29 threaded into the dies. The

location-l of thezpivot: points? onlpglates I 91 and 1 on dies 24 andf2zxis' preferably-such;that whenrthedies?- 2 I and: 22'" are in; abutting relation; and 1 irrengagement withthezwed'ge stripes and; as

shown in FigseIand 6 .the2:linkse21: and 2.3; will-be.- paral1el,-, vertical and. in alignment. with. one

another;;

It .will now; be apparent that-if dies =2.I and; 22: are: pulled horizontally toward: the left ,1 relativeto fixedzplaten .I 0, asviewed in Figs 1-.and.'.6; the parallelilinks 2-l-:and 28" will permit-such relative.

movement; and will,, at: the. same time, effect.

movement; ofthe :dies; in la'vertical directionzrela tive to" one." another: to a separated; position; as:

shownin Fig; 2; To-further assurerthatathe:diesi 2| and 22" will only move; vertically relative: to; one": another; several vertically disposed dowel.

pins 39 are secured 'in oneof? the dies. and pro:-

jected into borestin; the: other of said dies; said.

dowel pins being slidablee in '.such' bores: during;

relativemovementof the dies; However;,it ise-to. benoted that-win order. torbee able:to't'pu1l-.dies- 2'! and- 22 toward the -'1ef.t,= as described. abovee there must be-a lost: motion connectionbetween: laten I Zand therdie'sr2 I and 22 to, effect relative horizontal movement between them toadisengagez: the wedgesurfacesof stripsz24-anddies 2jand.

22'; Mean be clearly'seen fromFig, 6 ;4for.ex'-

must be -such=that it will. permitwvertical separation movementof the dieslas the horizontal We. have shown two forms; of suchconnection, viz;, that a movement of platen I2 continues.

of Figs. 1-8 and that of:Figs; 9-11. and such connections will now be-describedindetail.

In the formof connection shown in Figs. 1.-8

and particularly in Figs. 3,- 4 andi, eachdie is"- provided with a pair'of-longitudinal recesses from. each of 1 which a lug 3 I projects;- Slide guided in each such recess is a slide barr32 which isipro vided with-an elongated slot 33---surrounding.lug 3!.

the end wall 34 ofthe. recess inthesdiess likewise, that the lefte-hand end of-.slo.t33 never.

bar 32 canpartake. of-movernent toward the left,

asviewedin Figs. 1) and 4, r.elative1.to. the dies.. Such relative movement.v effects disengagementof'the wedge surfaces .of stripsfldt-fromethe'ldiesz-t Such relative movement. ceases? as: soon as. the. right-hand end wallof' slot; 33. en'-- Z! and 2.2..

gages with the right-hand end of. lug 31.- When:

such engagement. occurs, .the. dies 2 I and .22 will be pulled horizontally towardtheleft.inunison;

with slide bar.32'.'-

To yii z-ldaloly= retain the. right-liandend wall of slotisgin engagement'with the righti-handendi.

oflug 3i, thezsli'de b'ar 3'2.- has -a.bore.therein.in;

which an end'iof a rod; 35'. is urge'dlint'o engage ment with the left-hand end'oflug- 3| by means:-

of .a spring 36. which isccompressedrbetweenzthe other end oflrod 35.andv a.plug .31.threadedinto:

the outer end. of 'suchbore;

Having described. thehorizontal' lost motion connection, reference will. now. be made. to. that-:- part. of. the connection which. permits vertical.

It is preferred .that the'rightehand end of' the slide bar 32 be short-of. positively engaging; And;

separation; of? the; dies: simultaneously? during? horizontal. movement; thereofi. The: ban" 3.25 is? provided with anzinturned. end-1.38 whichiengag'es: in a vertical: jib 39;: definedv by auxiliary; platen: I 2 and plate 25. Thus, it can be seen'zthat'gasithezdies separate, the :end. 38i of slides-loan. 32; slides vertically; in. jib-3.9.

When a the: above-described mechanism. iSfi in the; position sho-wn-in -Figu 2: withrthe (116555813251 2 ratedafromone5another, the right-handendfiofif lug 3 I 'is-held in engagement with therigjht-hand endwall of slot 33by, means of spring 36.and md' 35. When the platen;I2wis;moved.toward1tliee rightithrough rod 3 and toggle; linkage-'- I5,. the

dies 21. and 2.2, will. move toward: the righttim unison with laten I2, thusv swinging. the links ZlandZB-toward an alignment-position and-cause ing-yrelative movementof the dies verticallyrelzat'- tive to "one anotherr. Such vertical movement 0f? the dies is permitted Icy-theslidingconnection?v between-slidezbar 32 aindxplaten v I2-'.-. Wherrxthee links-2'! and'28 reachan aligned positiom the" right-hand ends of the dies: aredisposed all): the: recess I in plate llbetweenv the wedge strips; 23' and, therefore, .furtherright-hand movement of; platen I2 will be relative tothediesiand thus; will .efiect-compressionoi spring? 3ttonbring" the vvectgez strips 24 into engagementwith the: left hand .ends of-.. the dies; From this point: on; thea high power right-hand. movement of platen i 2 effected by.- linkage I5-.- and thefurtherrmulti-plication: of such high. power movement by; the? wedge surfaces of strips'23-.-and 24 results inaitremendous: vertical clamping. force" to. firmlyholdthe. dies in engagement with-one another-1 As a matter" of fact,- such clamping; force' is? of. magnitude several times. that ofv the force exe' ertedthrough the toggle linkage fi. Therefore;

if the force exertible through toggle linkage-I 5f is"v suflicient in the'case of vertically disposed. dies; as shown .in Lester Patent 2,262,615, themechae nismmay be so adjusted that such force'is what inwhich case the stress. on. the linkage I 5 would i belbut a small fraction of that whichsuch linkage is-subjectedto in-thelmachine; disclosed in the-aforesaid patent.

Infinally closing the dies as described above. it is; to be understood that the ends ofithe dies. 2I.and 22do not engagethe bottoms- 0f therecesses. inthe plates. I'l and:2 5.- Also, if the links Hand 28 are. of lengthsuch thatsome:clamping. of Tthedies'isneifectedby the toggle action there oflwhenbeingswung into alignment, itcanlbeseen that compressive stresses; in .said: links are relieved by the: final closing action effected through the-wedge strips.-. Itispreferred; how-- ever that the dies.-just barelyor. lightly; engage one?- another when the-linksi 21 and 28- are in alignment; whereupon the-final closing: movement 1 effected by; the-interengagement of f thewedge" surfacestakes up thetolerancc:betweenthe linksand. their. respective pivots- 26- and 29. Such tolerance ispreferablyof the order of .001 .ofzan' inch .orless and;,therefore, by so-arrangingwhediesi and links,- nostress -of anyy kind isfimposed' on the links.

As to the: movement of platen:v I2 7 toward.- the" leftifrom theposition-ofFig; l-,,it-. canbeseen. that;the.-forces exerted through springs36- retaim the dies; 2|.- and- 22. in engagement. with wedge;

strips. 23 and4 thatsthe platen I2 can move-horie zontally relative to.thedies. toeffect disengage+- mentiofthe wedge strips 2 lrtherefrom. Whenthe. ht-:handlend .of..s1ot\33. in.slidelbar -3 2-enga s with the right-hand end of lug 3|, the dies are positively pulled away from plate and strips 23 and thus are moved horizontally in unison and at the same time are vertically separated from one another.

Inasmuch as the only difference between the mechanism of Figs. 9-11 and that of Figs. 1-8 is in the lost motion connection between the auxiliary platen I2 and the dies 2| and 22, the following description is restricted to such difference without repeating the general operation of the platen l2, the toggle linkage l5, the action of the wedge strips 23 and 24, etc.

As clearly shown in Figs. 9-11, plate 25 and each die is provided with brackets 40 and 4|. Links 42 and 43, pivotally connected to one another and to the brackets 40 and 4|, operate as the lost motion connection to permit relative horizontal movement of platen I2 and dies 2| and 22 and relative vertical movement of the dies and the platen l2. Link 43 is provided with op" positely extending arms M and 45, the former being engageable with die 2| or 22, as the case may be, and the latter being engaged by one end of a spring 45 which is compressed between die 2| or 22 and arm 45.

When the parts are in the position illustrated in Fig. 9, a force exerted toward the right by platen l2 eifects tight closing of the dies 2| and 22, the above-described lost motion connection permitting relative movement between platen l2 and platen |El, or between platen I2 and the dies 2| and 22. Now, if the platen I2 is moved toward the left, the effect of springs 46 is to hold the dies 2| and 22 in engagement with wedge strips 23 associated with plate Such relative movement continues until arm 45 of link 43 engages its respective die. At this time, the wedge strips 24 associated with plate 25 are out of engagement with the left-hand ends of the dies 2| and 22. The platen |2 then exerts a positive pull on the dies 2| and 22 to pull them toward the left and thus effect the swinging of the links 21 and 28 to eifect vertical separation of the dies as shown in Fig. 10. During separation of the dies, the links 42 swing to the position shown in Fig. 10.

During opposite movement of platen 2, that is toward the right, the springs 46 serve to retain arms 4 in engagement with the dies 2| and 22 until the right-hand ends of the dies are disposed within the recess in plate l! and in engagement with the wedge strips 23 therein. Thereafter lost motion movement occurs to compress the springs 45 and thereby effect the final clamping of the dies between the wedge strips 23 and 24.

To further exemplify the advantage of the present invention, we have illustrated in Figs. 6, '7 and 8 a typical die D comprising two sections, one of which is bolted to die-carrying member 2| and the other of which is bolted to die-carrying member 22. The dies herein illustrated include in their parting line the usual gates and runners 4? between the mold cavities 48 and the opening in the sprue bushing I8, inserts 49 extending into the cavities 58, and suitable insert holders G. The primary function of the holders 5% is to shorten the operating cycle of the machine by permitting loading of the several inserts 49 thereinto while the plastic material is being injected into and is setting in the cavities 48 in the batch previously placed in the machine. In other words, when the dies are separated as in Fig. 2, the holder and its several inserts can quickly be placed in the dies thus saving the time of placing the inserts one by one in the cavities 48.

As shown in the drawing, the dies D are also short of engaging the plates l1 and 25 as are the die-carrying members 2| and 22. In order to prevent leakage of plasticized material between the right-hand end of the dies and the lefthand end of the sprue bushing l8 during injection, these abutting surfaces are polished and lapped together to form a tight seal and are arranged to resiliently engage one another when the dies are in the finally closed position of Fig. 1. One manner of accomplishing such resilient engagement is to make the sprue bushing |8 of such length that it normally projects beyond the plate I! a distance exceeding the clearance between plate I! and the right-hand end of dies D whereby when the dies are moved to a finally closed position, the sprue bushing l8, the discharge nozzle 8 and the injection cylinder assembly 2 will be forced toward the right as viewed in Fig. 1, the strap 5| which straddles the opening at that end of the base being capable of yieldably bending in its mid section to permit such movement. The amount of such movement is, of course, very slight, preferably about .005 of an inch to assure firm yieldable engagement of the dies with the sprue bushing IE, but without danger of overstressing any of the parts.

From the above description relative to dies D, it can be seen that even for the simple inserts shown there would be considerable difliculty in holding the inserts in place between dies which are vertically disposed and movable horizontally relative to one another.

Another feature previously mentioned was that in making both die sections movable the ejector mechanism could be associated with either one or both depending on convenience rather than on necessity. In Figs. 6 and 7 we have shown one simple form of ejector mechanism which comprises ejector pins 52 carried by an ejector plate the pins being here engageable with one of the holders 5D to lift the same vertically upward relative to the lower die section when the dies are separated. The ejector plate 53 is slide guided vertically relative to die-carrying member 22 by rods 54 fixed therein. The relative vertical movement of the ejector mechanism relative to the lower die section is effected by interrupting movement of the ejector plate 53 during separation of the dies by means of an adjustable stop 55 carried by a bracket 56 attached to plate 25. While in most instances the molded article will remain or stick in the lower die section, there may be instances where it is desirable or necessary to provide an ejector mechanism in the upper die section, in which case the same can be very readily and conveniently accomplished in much the same manner as that just described. To those skilled in the art, it will be apparent that springs, push pins and the like may be employed with the ejector mechanism to assure that when the dies are in closed position the ends of the ejector pins, where they operate directly on the molded article, will be flush with the contour of the article. In the particular mechanism shown, the position of the ends of the ejector pins 52 is not critical just so long as the pins move downwardly far enough to permit full closing of the dies.

One advantage of the die actuating mechanisms herein disclosed which has not been especially emphasized in the preceding description is that the horizontal movement of the dies relative to the heated injection nozzle 8 while the casting is gripped between the dies assures that the sprue will always break away from the nozzle at the end of the nozzle where the material is soft and of smallest cross-section. As is well known to those skilled in the art, in conventional mechanisms breaking of the sprue from the gate or runners of the casting and the sticking thereof in the sprue bushing is an ever present problem causing considerable trouble and loss of time. Such undesirable breaking usually occurs when the juncture of the sprue and runners is soft as the die opens, or when the sprue cools and sticks in the sprue bushing. Of course, one manner of alleviating such problem has been to employ 59- called sucker pins but such can only be provided at added expense. In the present case such problem is simply and eifectively remedied without employment of sucker pins or the like.

As briefly indicated previously, the fact that both die sections are movable makes it possible to employ the ejector mechanism with either die section. In this way the ejector pins can conveniently be arranged to bear against unseen portions of the casting. In the conventional machines wherein only one die section is movable and the ejector mechanism is associated therewith and wherein the deepest portion of the casting is in such movable die for the purpose of increasing the adhesion between the casting and the die to assure that the casting will be retained in that die section which has the ejector mechanism, the ejector pins must, of necessity, he often brought to bear on surfaces of the casting which should preferably be smooth and free of all marks. In order to avoid such undesirable marring of the casting, die designers have often been called upon to design less efficient and harder to make dies, or else to redesign the article to be cast. Either case entails considerable expense, all of which can be avoided by making both dies movable so that the ejector mechanism, the deepest cavity, etc. can be embodied at will in either die.

An improved form of pivotal connection between the ends of links El, 23 and die carrying members 2 i, 22 and lug plates i9 is illustrated in Figs. 12 and 13. This connection, as shown, comprises a bushing 58, the opposite ends of which are respectively press fit and slip fit into openings in lug plate 53 and link 21. That end of bushing 58 which is press fitted into lug plate l is internally threaded for a portion of its length and the other end is counterbored as at 58. A bolt 65 in threaded engagement with threads formed in plate it and having a head portion within the counterbore 59 assures that the bushing will be retained against axial movement and rotation. The radially extending flange portion El of the bushing, in turn, retains the link against axial displacement relative to the bushing 58. Thus, it can be seen that the link 2'! can freely partake of pivotal movement about bushing 58 without tending to loosen the same. In other words, the press fitting of the bushing in plate 19 resists rotation of the bushing as does bolt 59. It is to be understood that the other end of link *2? is pivotally connected in the same manner with the bushing press fitted into one of the die carrying members.

If it be desired to disassemble the .die mechanism or to replace bushing 58, any bolt 62 having the same size threads as those in the bushing may be used. To remove bushing 58, bolt 553 is first removed and then such bolt 52 is merely screwed into the bushing. The engagementof the end of the bolt with thebottom wall 5.3 of the bore in plate 19 urges bushing 58 toward the right out of engagement with the bore in plate It, In Fig, 13 the bushing 58 is shown partially removed.

Othermodes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We therefore particularly point out and distinctly claim as our invention:

1. In a casting machine or the like, the combination of a pair of dies adapted to be relatively moved toward and away from one another, a pair of die actuating members relatively movable in opposite directions and transverse to such relative movement of said dies, means connecting said dies and members for moving said dies toward one another into closed position in response to relative movement of said members in one direction, and intereng ageable wedge means on said dies and said members for eifecting final closing of said dies upon continued relative movement of said members.

2. In a casting machine, the combination of a pair of dies adapted to be relatively moved toward and away from one another, a pair of members movable relative to one another in a direction transverse to such relative movement of said dies, and link means interconnecting said dies and members for moving said dies in opposite directions toward one another into closed position and away from one another into open position in response to relative movement of said members in opposite directions, said members and dies being formed with interengageable surfaces operative to effect final closing of the latter upon continued relative movement of said members in e di los n direct n- ;3. In a casting machine or the lik $119 Combination of a pair of dies adapted to be relatively moved toward and away from one another, and a pair of members movable relative to one another in a direction transverse to such relative movet o d di s, o h o sai m mber bein connected to at least one of said dies, the connection between one of said member and said one die comprising a link pivotally connected to each, said link being disposed at an angle relative to such transverse movement of said merribers at least when said dies are in closed position.

4 In a casting machine or the like, the combinaiion o a pa r .of di a apted t e r la iv ly moved toward and away from one another, a pair of members movable relative to one another in a direction transverse to such relative movement of said dies, both of said members being connected to at least one of said dies, the connectio bet e n o e of s d m mb rs and said one die comprising a link pivotally connected to each, said link being disposed at an angle relative to such transverse movement of said members at least when said dies are in closed position, and the connection between the other of said members and said one die comprising slidably engaged portions permitting a predetermined amount of relative movement of aid members independent of relative movement of said dies.

I a ca tin machine o t k th co bination of a pair ofdies adapted to be relatively moved toward and away from .oneanother, a

of members movable relative to one another in a said dies, and parallel links out of line with such transverse movement at least when said dies are closed, pivotally connected to each of said dies and to one of said members, the other of said members being connected to each of said dies so that relative movement of said members away from one another efiects swinging of said links toward alignment with such transverse movement and thus relative movement of said dies away from one another.

6. In a casting machine or the like, the combination of a pair of dies one above the other and movable relatively toward and away from one another, members movable horizontally relative to one another into and out of engagement with said dies, said dies and said members including wedge surfaces effective when engaged to urge said dies into engagement with one another, means vertically movably connecting both of said dies to one of said members, and link means connecting both of said dies to the other of said members, said link mean being disposed at an angle relative to the path of movement of said members at least when said dies are together whereby relative movement of said members away from one another efiects separation of said dies.

'7. In a casting machine or the like, the combination of a pair of dies adapted to be relatively moved toward and away from one another, a pair of die actuating members movable in a direction transverse to such relative movement of said dies into and out of engagement with said dies, said dies and said members including wedge surfaces effective when engaged to urge said dies into engagement with one another, link means connecting one of said members to said dies, and lost motion connecting means between the other of said members and said dies for effecting disengagement of such wedge surfaces upon relative movement of said members away from one another, said link means being disposed angularly relative to the path of relative movement of said members at least when the aforesaid wedge surfaces are disengaged whereby continued movement of said members effects separation of said dies.

8. In a casting machine or the like, the combination of a pair of dies adapted to be relatively moved toward and away from one another, relatively movable members movable in a direction transverse to such relative movement of said dies, means for translating movement of said members into movement of said dies, said means including a lost motion connection between said members and said dies for permitting limited relative movement of said members prior to efiecting relative movement of said dies, said lost motion connection comprising a lug on each of said dies, a slide member fitted over said lug and slidable transversely on each of said dies and connected to one of said members, said slide member being formed with an elongated slot therein one end of which is engageable with said lug to efiect relative movement of said dies in response to further relative movement of said members.

9. In a casting machine or the like, the combination of a pair of dies adapted to be relatively moved toward and away from one another, relatively movable members movable in a direction transverse to such relative movement of said dies, means for translating movement of said members into movement of said dies, said means including a lost motion connection between said members and said dies for permitting limited relative movement of said members prior to effecting relative movement of said dies, said lost motion connection comprising a lug on each of said dies, a slide member fitted over said lug and slidable transversely on each of said dies and connected to one of said members, said slide members being formed with an elongated slot therein one end of which is engageable with said lug to eifect relative movement of said dies in response to further relative movement of said members, and a spring urging said slide member toward a position with such end in engagement with said lug.

10. In a casting machine or the like, the combination of a pair of dies adapted to be relatively moved toward and away from one another, relatively movable members movable in a direction transverse to such relative movement of said dies, means for translating movement of said members into movement of said dies, said means including a lost motion connection between said members and said dies for permitting limited relative movement of said members prior to effecting relative movement of said dies, said lost motion connection comprising a link pivotally connected to each die and to one of said members, said link including an arm engageable with said die to effect relative movement of said dies in response to further relative movement of said members.

11. In a casting machine or the like, the combination of a pair of dies adapted to be relatively moved toward and away from one another, relatively movable members movable in a direction transverse to such relative movement of said dies, means for translating movement of said members into movement of said dies, said means including a lost motion connection between said members and said dies for permitting limited relative movement of said members prior to effecting relative movement of said dies, said lost motion connection comprising a link pivotally connected to each die and to one of said members, said link including an arm engageable with said die to effect relative movement of said dies in response to further relative movement of said members, and a spring compressed between said die and said link urging said arm into engagement with said die.

12. In a casting machine or the like, the combination of a fixed member formed with an opening therethrough, a horizontally disposed injection nozzle in such opening, vertically separable and horizontally movable dies formed with a molding cavity and defining when closed a sprue in their parting line in register with said nozzle, a horizontally movable member spaced from said fixed member and movable toward said fixed member to clamp said dies, said members and said dies including wedge surfaces to translate such horizontal clamping force into a vertical die closing force, means connecting said dies with said movable member, and link means connecting said dies with said fixed member and so arranged as to be responsive to movement of said movable member away from said fixed member to separate said dies.

'13. In a casting machine, the combination of a pair of vertically disposed and relatively horizontally movable die clamping members, a pair of side plates on one of said members extending toward the other of said members, a pair of dies between said members having a horizontal parting line, parallel link mechanisms connecting said dies to said plates for swinging movement of the former toward and away from one another, and mean connecting said other of said members 75 to said dies whereupon relative horizontal movemet of said members in opposite directions effects swinging of said dies as aforesaid, the opposed vertical faces of said members and the opposite ends of said dies being formed with interengageable wedge surfaces operative when said members are moved toward one another into engagement with the dies therebetween to clamp the latter together.

14. In a casting machine, the combination of a pair of vertically disposed and relatively horizontally movable die clamping members, a pair of side plates on one of said members extending toward the other of said members, a pair of dies between said members having a horizontal parting line, parallel link mechanisms connecting said dies to said plates for swinging movement of the former toward and away from one another, and means connecting said other of said members to said dies whereupon relative horizontal movement of said members in opposite directions effects swinging of said dies as aforesaid, the op-.

posed vertical faces of said members and the opposite ends of said dies being formed with interengageable wedge surfaces operative when said members are moved toward one another into engagement with the dies therebetween to clamp the latter together, said last-named means comprising bars vertically slidably connected to said other of said members and connected to said dies.

15. In a casting machine, the combination of a pair of vertically disposed and relatively horizontally movable die clamping members, a pair of side plates on one of said members extending toward the other of said members, a pair of dies between said members having a horizontal parting line, parallel link mechanisms connecting said dies to said plates for swinging movement of the former toward and away from one another. and means connecting said other of 40 said members to said dies whereupon relative horizontal movement of said members in opposite directions efiects swinging of said dies as aforesaid, the opposed vertical faces of said members and the opposite ends of said dies being formed with interengageable wedge surfacesoperative when said members are moved toward one another into engagement with the dies there between to clamp the latter together, said lastnamed means comprising bars vertically slidably connected to said other of said members and connected to said dies, the connection of said bars with said dies including a horizontal lostmotion connection so formed that such wedge surfaces on said members and dies are disengaged in response to relative movement of said members away from one another and prior to swinging of the dies away from one another upon continued movement of said members away from one another.

NATHAN LESTER. THOMAS J. LESTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Lester et a1 Dec. 19, 1944 

